Mechanism for slotting the heads of screws.



G. T. WARWICK. MECHANISM FOR SLOTTING THE HEADS OF SCREWS.

APPLICATION FILED MAR.13, 1912.

1,082,720. Patented Dec. 30, 1913.

ATTORNEY.

UNITED STATES PATENT OFFICE.

GEORGE T. WARWICK, OF SPRINGFIELD, MASSACHUSETTS, ASSIGNOR T0 INTERNA- TIONAL MACHINE AND SCREW COMPANY, OF SPRINGFIELD, MASSACHUSETTS, A

CORPORATION OF MAINE.

MECHANISM FOR SLOTTING TI-IE HEADS OF SCREWS.

noearao.

Specification of Letters Patent.

Patented Dec. 30,1913.

To all whom it may concern:

Be it known that I, GEORGE T. lVARwroK, a citizen of the United States of America, and resident of Springfield, in the county of Hampden and State of Massachusetts, have invented certain new and useful Improvements in Mechanism for Slotting the Heads of Screws, of which the following is a full, clear, and exact description.

This invention has for its object to provide a device for forming the slot in the head of screws or bolts by forcing the metal laterally in the direction of the slot and outward on each side thereof.

A further object is to provide in such a device means whereby the metal will be caused to project at each side of the slot in the form of fins, and thereupon such fins will be severed, and the faces of the blank at such cutting portions will be left even, and no burs formed.

In the accompanying drawings, showing one embodiment of my invention: Figure 1 is a vertical axial section through the die and the lower portion of the punch member; Fig. 2 is a similar view with the die advanced a short distance farther than shown in Fig. 1, with the fins formed and partly severed. Fig. 3 is a similar view with the die moved down and the fins severed. Fig. 4 is a plan view of the die. Fig. 5 is a cross section on the line 5 5, Fig. 2. Fig. 6 is a vertical section taken at right angles to Fig. 1; and Fig. 7 is a cross section on the line 88 of Fig. 6.

As shown in Fig. 1, a die member 12 has an axial bore 13 for receiving the screw blank F, and at the top the bore is made flaring corresponding to the usual conical head formed on screws and bolts of certain kinds; and the die is provided with a diametral slot extending across, forming two slotted portions 14 and 15, that are of comparatively shallow depth, and these parts are so proportioned relative to the blank that the head of the screw will project into the slotted portion of the die, and the bottom wall of these slotted portions is shown in Figs. 13 at 16 and 17 as inclined downwardly and outwardly from the flaring or inclined portion of the bore in the die, thereby forming a cutting edge on each side which will cooperate with the punch member to sever the metal which is forced outward in the formation of the slot.

The cooperating part of the punch is in the form of a thin blade 18, which is shown as carried by a punch body 19; and it will be understood that the punch is suitably guided for movement toward and from the die member. The blade is of a thickness corresponding to the slotted portions 14 and 15 in the die member to enter such slots when brought down, when it will evidently engage the top of the blank where the slot is to be formed; and at such portion the blade is curved or formed convex with the lowest portion at the center of the blank to engage the blank first at this portion.

As the blank is supported in the die at all parts of the conical head except at the extremities of the slotted portions of the die, the metal at such portion is free to be forced outwardly, which is effected by reason of the curved form of the punch blade, and projections or fins 21 and 20 are produced by the stock of the blank flowing outward in opposite directions; and this is facilitated by reason of the cut away portions in the slot-s.

It will be observed from Fig. 1 that the cutting portions formed by the inclined walls 16 and 17 will have the tendency to sever these fins, coacting with the opposite portions of the blade at its curved extension; should the punch be further advanced, these cutting edges and the blade will act to shear off these fins and complete the operation, leaving a slot in the blank where the metal was forced away.

In the modification of the punch shown in Fig. 6 a holding or stripping member is provided, in the form of a plunger 45 sliding in a bore 4-6 in the punch 54 in the die 80, which is slotted at its lower end to straddle the blade 10; a spring A? back of the plunger forcing it down to normally project a short distance beyond the lower edge of the blade, to engage the head of the blank before the blade descends, so that when the punch is withdrawn after the operation, the plunger will be moved downward by its spring and strip the blank from the blade.

In the views it will be seen that openings 50 and 51 are provided on each side through the bore and extend down from the slotted portions, which will permit the escape of the fins, when severed.

I claim:

1. A slotting tool composed of a die member and a punch, the die member comprising a body having a bore formed with a flare at the upper end portion to support a screw blank with a conical head, the die having a diametral slot extending across the bore at the upper part that is of short dept-h, the die member having an opening extending down from the slotted portion on each side through the body, the slotted portion on each side having the bottom wall inclined downward and outward from said flaring wall of the bore to the said openings to form sharply acute cutting edges, and a punch in the form of a blade arranged to enter the slot in the die to engage the top of the blank therein and force the metal outward on each side through said slotted portions of the die to form a slot in the blank.

2. A slotting tool composed of a die member and a punch, the die member comprising a body having a bore formed with a flare at the upper end portion to support a screw blank with a conical head, the die having a diametral slot extending across the bore at the upper part that is of short depth, the die member having an opening extending down from the slotted portion on each side through the body, the slotted portion on each side having the bottom wall inclined downward and outward from said flaring wall of the bore to the said openings to form sharply acute edges, and a punch in the form of a blade arranged to enter the slot in the die to engage the top of the blank therein and force the metal outward on each side through said slotted portions of the die to form a slot in the blank, the punch blade being longitudinally curved on its lower edge to engage the blank at the center portion first.

3. A slotting tool composed of a die member and a punch, the die member comprising a body having a bore formed with a flare at the upper portion to support a screw blank with a conical head, the die having a diametral slot extending across the bore at the upper part and of short depth, the punch being in the form of a blade arranged to enter the slot in the die and engage the top of the blank therein and force the metal outward on each side through said slotted portions of the die to form a slot in the blank, the die member having an opening extending down from the slotted portion on each side and through the body.

4. A slotting tool composed of a die member and a punch, the die member comprising a body having a bore formed with a flare at the upper portion to support a screw blank with a conical head, the die having a diametral slot extending across the bore at the upper part of short depth, the punch being in the form of a blade arranged to enter the slot in the die and engage the top of the blank therein and force the metal outward on each side through said slotted portions in the die to form a slot in the blank, the die having an opening down from the slotted portion on each side and through the body, the punch being longitudinally curved on its lower edge to engage the blank at the center first.

Signed by me at Springfield, Mass, in presence of two subscribing witnesses.

GEO. T. XVARVVIOK.

Witnesses:

V'M. S. BELLows, G. R. DRISCOLL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents Washington, D. C. 

